The present invention relates to a door latch assembly which is easily adjusted for mounting on doors of differing thickness. More specifically, such adjustment is effected in a way that provides the assembly with inherent strength and avoids the need for threading on components. The latch assembly may include means for locking the door, such as a well-known cylinder door lock.
Passage sets and lock sets generally comprise a housing having spindles extending centrally outward from either side. The housing is adapted to be disposed in an opening through the door and includes a mechanism for latching the door closed. On the outside of the door a handle and rose assembly fit onto the housing such that the handle cooperates with one of the spindles of the housing to operate the latch. The rose assembly is threaded on the outside of the housing and held from rotation by engagement with the door.
On the inside of the door, the handle has a rose liner provided with openings to receive bolts which extend into the housing. In assembly, the liner is bolted to the housing. A rose scalp is brought over the spindle and affixed to the liner, and the handle is then snapped into place over the spindle. Alternatively, the inside rose may be an assembly which is threaded onto the inside spindle to pull the rose tightly against the door. The handle is then assembled over the spindle.
Mounting the passage or lock set has typically involved the steps of adjusting the position of the outside handle and rose assembly on the outer spindle according to the thickness of the door. The inside rose liner is then threaded onto the inside spindle or is bolted onto the cylindrical housing until the liner is snug against the door. The mounting will require more or less threading or bolting of the inside rose plate onto its spindle depending on the thickness of the door. This conventional latch installation involves the manipulation of several parts and takes considerable time. It also requires threading on certain components and other structure to provide the necessary rotational stability to the assembly, all of which adds cost.
Since the passage of the Americans with Disabilities Act (ADA) which requires equal access for handicapped persons, lever handles have become prevalent on doors. Lever handles provide the user with the ability to apply much greater torque to door latch and lock assemblies, requiring developments in passage set technology to withstand such forces.
Another recurring concern with regard to passage sets is the requirement for mounting on doors of differing thickness. As described above, this has traditionally been accomplished through the use of threaded components.